Abstract: A tissue stimulation device includes an electrode array having at least four independently switchable electrodes. In one embodiment, the electrode array comprises a flexible base to which the electrodes are fixed that flexes to encompass at least a portion of an artery or other elongate biological structure. The electrodes are electrically coupled to and energized by a signal generator coupled to a control system. In one embodiment, the array of electrodes are configured such that a suitable signal pattern for stimulation pulses between or among a set of the switchable electrodes may be determined without having to reposition the electrode assembly by using a series of signal patterns activating different combinations of switchable electrodes in response to sub-stimulation test signals to determine a signal pattern that provides suitable patient response. In another embodiment, the array of electrodes includes an array of selectively activatable multi-polar electrodes.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohornonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably in the carotid sinus. The baroreceptor activation device may utilize electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, for example a baroreceptor in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably in the carotid sinus. A mapping method permits the baroreceptor activation device to be precisely located to maximize therapeutic efficacy.

Abstract: Baroreflex activation is achieved by providing suitable control signals to a baroreflex activation device. A method comprises establishing a therapy interval (possibly on the order of minutes to hours, or possibly of indefinite duration), within the therapy interval, establishing a plurality of dose intervals, and generating an electrical output signal. The electrical output signal has a time dependence such that the average electrical power applied to the baroreflex activation device differs between first and second portions of at least some dose intervals. Another method comprises establishing a series of therapy interval portions, during at least some therapy intervals, establishing a plurality of burst intervals (perhaps having durations commensurate with an interval between heartbeats), and generating an electrical output signal.

Abstract: Devices, systems and methods are disclosed by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably a baroreceptor located in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption. The baroreceptor activation device may utilize RF-coupled or other electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

Abstract: Devices, systems and methods are described by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably a baroreceptor located in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption. The baroreceptor activation device may utilize electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

Abstract: Devices, systems and methods by which the real or apparent renovascular perfusion and intrarenal pressure may be selectively and controllably increased. By selectively and controllably increasing renovascular perfusion and interstitial hydrostatic pressure when the heart is unable to pump sufficient blood or when renal perfusion is suboptimal, the present invention reduces or reverses neurohormonal activation and fluid retention, and thereby minimizes their deleterious effects on the heart, vasculature, kidneys and other body systems.

Abstract: Devices, systems and methods by which the real or apparent renovascular perfusion and intrarenal pressure may be selectively and controllably increased. By selectively and controllably increasing renovascular perfusion and interstitial hydrostatic pressure when the heart is unable to pump sufficient blood or when renal perfusion is suboptimal, the present invention reduces or reverses neurohormonal activation and fluid retention, and thereby minimizes their deleterious effects on the heart, vasculature, kidneys and other body systems.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, for example a baroreceptor in the carotid sinus. A control system may be used to modulate the baroreceptor activation device. The control system may utilize an algorithm defining a stimulus regimen which promotes long term efficacy and reduces power requirements/consumption.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohornonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably in the carotid sinus. The baroreceptor activation device may utilize electrodes to activate the baroreceptors. The electrodes may be adapted for connection to the carotid arteries at or near the carotid sinus, and may be designed to minimize extraneous tissue stimulation.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. A baroreceptor activation device is positioned near a baroreceptor, preferably in the carotid sinus. A mapping method permits the baroreceptor activation device to be precisely located to maximize therapeutic efficacy.

Abstract: An implantable medical device determines activity levels and Heart Rate and from a combination of these produces a value for a heart rate activity coefficient (HRAC). This value has significant diagnostic and patient tracking value. Methods and apparatus for determining this HRAC value are described. This enables physician review of patient cardiac status. Additional physiologic data can be recorded along with the HRAC data if desired, and this too, as well as the HRAC data alone, may be reported out from the implanted device to a medical communications system for alarm purposes, titrating drugs/therapies or other monitoring tasks. Further, substitutes for heart rate measurements and activity measurements are described which can be used to augment or substitute for heart rate measurements and activity measurements.

Abstract: Devices, systems and methods by which the blood pressure, nervous system activity, and neurohormonal activity may be selectively and controllably reduced by activating baroreceptors. By selectively and controllably activating baroreceptors, the present invention reduces excessive blood pressure, sympathetic nervous system activity and neurohormonal activity, thereby minimizing their deleterious effects on the heart, vasculature and other organs and tissues. A baroreceptor activation device is positioned near a baroreceptor, preferably in the carotid sinus and/or the aortic arch. The baroreceptor activation device may comprise a wide variety of devices which utilize mechanical, electrical, thermal, chemical or biological means to activate the baroreceptor. A control system may be used to generate a control signal to modulate the baroreceptor activation device.

Abstract: An implantable medical device determines activity levels and Heart Rate and from a combination of these produces a value for a heart rate activity coefficient (HRAC). This value has significant diagnostic and patient tracking value. Methods and apparatus for determining this HRAC value are described. This enables physician review of patient cardiac status. Additional physiologic data can be recorded along with the HRAC data if desired, and this too, as well as the HRAC data alone, may be reported out from the implanted device to a medical communications system for alarm purposes, titrating drugs/therapies or other monitoring tasks. Further, substitutes for heart rate measurements and activity measurements are described which can be used to augment or substitute for heart rate measurements and activity measurements.

Abstract: An implantable medical device for treatment of cardiovascular disorders by stimulating a selective nerve, the device including an implantable pulse generator, an implantable electrode body and a reservoir. The electrode body includes an electrode electrically connected to the pulse generator. Further, the electrode body is configured to sustain long-term contact between the electrode and the nerve. The reservoir maintains a nerve stimulating drug, such as a veratrum alkaloid, and defines a delivery surface through which the drug is released from the reservoir. Finally, the reservoir is operatively associated with the electrode body to deliver the nerve stimulating drug directly to the nerve. During use, the electrode and the delivered drug stimulate the nerve to effect control over the cardiovascular system of the patient.

Abstract: A system and method for stimulating the baroreflex arc based on levels of indicators from the body includes a pacemaker for bradycardia support pacing should the indicators show the need for support pacing. Other indicators and a process take advantage of an assumed relationship between peripheral vascular resistance and pulmonary resistance to determine the level of nerve stimulation required. This level is adjusted or optimized based on its interaction with heart activity and changes in the other indicators. These other indicators are readily available to the implanted device and allow for a process to make an estimate of pulmonary vascular resistance, from which SVR is also estimated. The value determined for SVR is the primary value used to determine the level of nerve stimulation absent indicators for the need to provide bradicardia pacing. The pacemaker can be rate responsive, as can the process for determining the level of nerve stimulation to be delivered.

Abstract: An anodal stimulation method and apparatus for the prevention or treatment of tachyarrhythmias using anodal stimulation (AS) energy for effecting hyperpolarization of myocardial cells of a heart chamber to enhance the relaxation thereof in the diastolic phase and to enhance cardiac function, reverse or inhibit cell activation, and thereby treat or prevent tachyarrhythmias. In a preemptive mode with a recognizable ventricular rhythm, the AS pulse is optimally timed to be delivered in an AS delivery interval following an AS delay interval timed from a preceding ventricular depolarization to effect maximal cardiac relaxation and suppress aberrant electrical activity. In a reactive mode responsive to a detected tachyarrhythmia requiring delivery of an anti-tachyarrhythmia therapy, e.g. a cardioversion shock therapy, the AS pulse is delivered during charging of high voltage output capacitors providing the cardioversion shock energy.

Abstract: An implantable system providing cardiac anodal stimulation (AS) as a system for effecting hyperpolarization of myocardial cells of a heart chamber to enhance the relaxation thereof in the diastolic phase and to thereby enhance cardiac function. The AS system is optimally timed to be delivered in an AS delivery interval following an AS delay interval timed from a preceding ventricular depolarization or pacing pulse to effect maximal cardiac relaxation. The sub-threshold AS pulse or train of pulses is increased in energy (amplitude) and/or decreased in energy to and from a peak energy level gradually rather than abruptly. The AS characteristics are optimized in an initialization process that determines the AS characteristics that provide the optimum blood pressure parameters and thereafter continually or from time to time in a confirmation process.

Abstract: A dual chamber pacemaker is provided having capability for adjusting the AV escape interval so as to optimize the timing of delivered ventricular pace pulses for therapy of patients with cardiomyopathy. The pacemaker system continually monitors to determine when a delivered pace pulse results in a fusion beat, and periodically adjusts the AV escape interval in accordance with the percentage or rate of incidence of such fusion beats. In one specific embodiment, the pacing system determines the percentage of delivered ventricular pace pulses which are followed by fusion beats over a predetermined number of intervals, and decrements AV escape interval when such percentage is not below a predetermined minimum. The pacing system also periodically increments AV escape interval when the rate of fusion beats is acceptable, thereby providing a closed loop system for maintaining the AV interval at an optimally long value consistent with maximizing full capture by delivered ventricular pace pulses.